(1) Field of the Invention
The invention relates to a process for mixing materials in bulk during passage through a mixing silo, a plurality of discharge openings being provided, spaced apart from each other, in the floor region of the silo, the material being withdrawn from these openings in a differentially controlled manner, so that different descent velocities are established, zone by zone, in the material contained in the silo. The invention further relates to a mixing silo for carrying out this process.
(2) Description of the Prior Art
In a known process of this type (Periodical: Aufbereitungstechnik, 1977, Page 566, FIG. 3), the silo floor is provided with aerating devices, and is inclined towards the centre, while a discharge chamber is provided in the centre of the floor, a large number of openings being distributed in the wall of this chamber, through which openings the material is withdrawn from the silo.
The eccentric arrangement of the discharge openings causes the material stored in the silo to form a plurality of eccentric discharge vortices. The term "vortex" is to be understood as that region in the bulk material, above a discharge opening, which moves downwards, during the withdrawal of material, more quickly than the surrounding material.
In the case of another silo, which is not specifically designated as a mixing silo, it is additionally known (from German Offenlegungsschrift No. 2,336,984) that the silo floor, which is provided with aerating devices, can be allowed to run with an inclination in the outward direction to a large number of peripherally located discharge openings which emerge into an annular passage located within the silo wall, under a slope which encircles the silo floor. Air can be admitted to the aerating devices on the silo floor, which are assigned to the individual discharge openings, at regular intervals and in different amounts.